Karl Widerquist discusses how UBI functions, showing how it differs from other redistributional approaches. He summarizes the common arguments for and against UBI and presents the reasons for believing it is a tremendously important reform. The book briefly discusses the likely cost of UBI; options for paying for it; the existing evidence on the probable effects of UBI; and the history of UBI from its inception more than two hundred years ago through the two waves of support it received in the twentieth century to the third and largest wave of support it is experiencing now.